polar_get_heart_rate

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds useful behavioral context beyond the annotations by mentioning that the response always includes heart rate zone summaries and daily statistics, and that data is preprocessed into half-hourly buckets. It does not address side effects, auth requirements, or rate limits, but annotations already cover the read-only, idempotent nature.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences long and directly conveys the key facts: the action, the data type, the aggregation, and the guaranteed return fields. There is no redundancy or extraneous information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the simple parameter set (3 parameters, no nested objects) and lack of an output schema, the description provides sufficient context for an agent to understand what the tool does and what it returns. No additional details are necessary for basic usage.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema provides 100% coverage with descriptions for all three parameters (from, to, format). The description does not add any additional parameter-level guidance beyond what is in the schema, so the baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: retrieving continuous heart rate data for a date range. It also specifies the data granularity (half-hourly buckets) and that it always returns zone summaries and daily statistics, making it distinct from other Polar health tools like sleep or cardio load.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not explicitly state when to use this tool over alternatives. It simply describes what the tool does, relying on the tool name and sibling context for differentiation, which is insufficient guidance for an agent deciding between tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.